I have a weird one!
I have a "Pinnacle PCTV Stereo" TV Card with TV and S-Video inputs that I've used with MythTV before (in SuSE) without any problems.
Now, for some reason, the card detects OK under the "Capture cards" menu, but I can't add any video sources under "Input Connections" for the tuner or the S-Video inputs --> the only option I have is "(None)".
I've tested it in xawtv and TVTime and it works fine.
Anyone got any ideas?